Congenital anomalies in relation to the use of doxylamine/dicyclomine and other antenatal factors: an ongoing prospective study.

Recent publicity regarding possible teratogenic effects of the doxylamine/dicyclomine/pyridoxine combination (Debendox) has led to a degree of apprehension in women for whom the drug is prescribed, and in doctors who prescribe it. This study, based on an ongoing epidemiological surveillance programme, reports an analysis of the records of 1817 women for whom the drug was prescribed compared with 5771 non-users. The object of the study was to evaluate the outcome of pregnancy against exposure to the drug, taking into account the coexistent influences of other factors. Thorough statistical analysis disclosed no evidence of teratogenicity of the doxylamine/dicyclomine/pyridoxine overall, nor in relation to the skeletal or cardiovascular systems in particular. Two unexpected findings were an apparent moderate increase in genital tract abnormalities in users of this drug, and the possibility of a synergistic relationship between tobacco and this drug in early pregnancy, both aspects warranting further investigation.